3-Digit Addition Worksheet - Practice Problems for Elementary Math Students

Here are the solutions for the addition problems on the sheet. I have worked through each one carefully to ensure accuracy.

Step-by-Step Solutions:

1) 478 + 357
- Ones: $8 + 7 = 15$ (write 5, carry 1)
- Tens: $7 + 5 + 1 (\text{carry}) = 13$ (write 3, carry 1)
- Hundreds: $4 + 3 + 1 (\text{carry}) = 8$
- Result: 835

2) 148 + 363
- Ones: $8 + 3 = 11$ (write 1, carry 1)
- Tens: $4 + 6 + 1 (\text{carry}) = 11$ (write 1, carry 1)
- Hundreds: $1 + 3 + 1 (\text{carry}) = 5$
- Result: 511

3) 518 + 437
- Ones: $8 + 7 = 15$ (write 5, carry 1)
- Tens: $1 + 3 + 1 (\text{carry}) = 5$
- Hundreds: $5 + 4 = 9$
- Result: 955

4) 253 + 316
- Ones: $3 + 6 = 9$
- Tens: $5 + 1 = 6$
- Hundreds: $2 + 3 = 5$
- Result: 569

5) 273 + 508
- Ones: $3 + 8 = 11$ (write 1, carry 1)
- Tens: $7 + 0 + 1 (\text{carry}) = 8$
- Hundreds: $2 + 5 = 7$
- Result: 781

6) 476 + 59
- Ones: $6 + 9 = 15$ (write 5, carry 1)
- Tens: $7 + 5 + 1 (\text{carry}) = 13$ (write 3, carry 1)
- Hundreds: $4 + 1 (\text{carry}) = 5$
- Result: 535

7) 683 + 126
- Ones: $3 + 6 = 9$
- Tens: $8 + 2 = 10$ (write 0, carry 1)
- Hundreds: $6 + 1 + 1 (\text{carry}) = 8$
- Result: 809

8) 475 + 286
- Ones: $5 + 6 = 11$ (write 1, carry 1)
- Tens: $7 + 8 + 1 (\text{carry}) = 16$ (write 6, carry 1)
- Hundreds: $4 + 2 + 1 (\text{carry}) = 7$
- Result: 761

9) 607 + 195
- Ones: $7 + 5 = 12$ (write 2, carry 1)
- Tens: $0 + 9 + 1 (\text{carry}) = 10$ (write 0, carry 1)
- Hundreds: $6 + 1 + 1 (\text{carry}) = 8$
- Result: 802

10) 368 + 409
- Ones: $8 + 9 = 17$ (write 7, carry 1)
- Tens: $6 + 0 + 1 (\text{carry}) = 7$
- Hundreds: $3 + 4 = 7$
- Result: 777

11) 254 + 63
- Ones: $4 + 3 = 7$
- Tens: $5 + 6 = 11$ (write 1, carry 1)
- Hundreds: $2 + 1 (\text{carry}) = 3$
- Result: 317

12) 165 + 427
- Ones: $5 + 7 = 12$ (write 2, carry 1)
- Tens: $6 + 2 + 1 (\text{carry}) = 9$
- Hundreds: $1 + 4 = 5$
- Result: 592

13) 391 + 264
- Ones: $1 + 4 = 5$
- Tens: $9 + 6 = 15$ (write 5, carry 1)
- Hundreds: $3 + 2 + 1 (\text{carry}) = 6$
- Result: 655

14) 816 + 75
- Ones: $6 + 5 = 11$ (write 1, carry 1)
- Tens: $1 + 7 + 1 (\text{carry}) = 9$
- Hundreds: $8$
- Result: 891

15) 272 + 385
- Ones: $2 + 5 = 7$
- Tens: $7 + 8 = 15$ (write 5, carry 1)
- Hundreds: $2 + 3 + 1 (\text{carry}) = 6$
- Result: 657

16) 504 + 38
- Ones: $4 + 8 = 12$ (write 2, carry 1)
- Tens: $0 + 3 + 1 (\text{carry}) = 4$
- Hundreds: $5$
- Result: 542

17) 476 + 284
- Ones: $6 + 4 = 10$ (write 0, carry 1)
- Tens: $7 + 8 + 1 (\text{carry}) = 16$ (write 6, carry 1)
- Hundreds: $4 + 2 + 1 (\text{carry}) = 7$
- Result: 760

18) 616 + 257
- Ones: $6 + 7 = 13$ (write 3, carry 1)
- Tens: $1 + 5 + 1 (\text{carry}) = 7$
- Hundreds: $6 + 2 = 8$
- Result: 873

19) 293 + 246
- Ones: $3 + 6 = 9$
- Tens: $9 + 4 = 13$ (write 3, carry 1)
- Hundreds: $2 + 2 + 1 (\text{carry}) = 5$
- Result: 539

20) 356 + 188
- Ones: $6 + 8 = 14$ (write 4, carry 1)
- Tens: $5 + 8 + 1 (\text{carry}) = 14$ (write 4, carry 1)
- Hundreds: $3 + 1 + 1 (\text{carry}) = 5$
- Result: 544

21) 778 + 95
- Ones: $8 + 5 = 13$ (write 3, carry 1)
- Tens: $7 + 9 + 1 (\text{carry}) = 17$ (write 7, carry 1)
- Hundreds: $7 + 1 (\text{carry}) = 8$
- Result: 873

22) 230 + 384
- Ones: $0 + 4 = 4$
- Tens: $3 + 8 = 11$ (write 1, carry 1)
- Hundreds: $2 + 3 + 1 (\text{carry}) = 6$
- Result: 614

23) 517 + 224
- Ones: $7 + 4 = 11$ (write 1, carry 1)
- Tens: $1 + 2 + 1 (\text{carry}) = 4$
- Hundreds: $5 + 2 = 7$
- Result: 741

24) 495 + 358
- Ones: $5 + 8 = 13$ (write 3, carry 1)
- Tens: $9 + 5 + 1 (\text{carry}) = 15$ (write 5, carry 1)
- Hundreds: $4 + 3 + 1 (\text{carry}) = 8$
- Result: 853

Final Answer:
1) 835
2) 511
3) 955
4) 569
5) 781
6) 535
7) 809
8) 761
9) 802
10) 777
11) 317
12) 592
13) 655
14) 891
15) 657
16) 542
17) 760
18) 873
19) 539
20) 544
21) 873
22) 614
23) 741
24) 853